Smartwool  Classic Thermal Merino Base Layer Crew One-Piece - Men's

I got this for a couple of reasons, one being that it's absolutely cool to have a set of handsome looking old school Long Johns but also because I'm used to Smartwools legendary quality from their base layers and accessories. Highly recommend this if you do cold weather sports or want a comfortable onesie for around the house in the winter time. Larger front zipper helps to purge excess heat and the drop flap in the back was great for bathroom breaks. I got it a size larger than I usually wear to reduce overheating and I'm glad I did cuz it's warm!!

Finally smartwool made a suit! I bought it for Smartwool's reliability and quality materials. I am a very active aggressive snowboarder and a big-time Gear Nerd. I recommend this suit, it's very comfortable and the material is amazing. BUT I'll be honest about what I would change. . . 1) As a base layer, it fits loose. the torso and arms are roomy. I think this suit should be tighter to allow for easier layering over it. I am curious about trying a smaller size. 2) A draw string around the waist would be beneficial. It provides structure by anchoring the suit to the body in one place. Otherwise, great suit! SHOUT OUT for the gusseted crotch, the fabric lining inside the zipper, the open fly, and the seams making up the shoulder construction.

It is extremely well made and so comfortable. You barely feel you are wearing anything and it keeps you warm. I am 5'11' a weight 148lbs. I wasn't sure if I should pick a medium or a small. The small is actually a little big for me, just long enough for both legs and sleeves, but the waist is way too large. It would also be nice if the bottom of the legs were narrower so I could put my (Smartwool) ski socks over them. I leave my socks under neath and can roll up the legs above my ski boots.

Fits great, feels comfortable, and is nice and warm!

The main reason I got this is to wear under my kayaking dry suit in warmer weather. It is replacing a 30-year-old poly union suit. I was happy to find something without a hood for more comfort and usability with the neck gasket. Also, no hood gives me more flexibility when dressing for really cold temps. Hoods can be annoying when all your go to layers have one.

Amazing addition to my arsenal against the Chicago winter. Comfortable: I do not notice the nicely tucked butt zipper. I am a city folk, but country people might like this for camping and outdoors activities. I need this for waiting at the trainstop by the blustery shores of Chicago's Lake Michigan.

These are my baselayers on the coldest days. I am a mountain guide in the Mount Washington Valley. Winters here can be brutal. I bust this piece out on the coldest of days. This thing seals out the cold. Warm, comfortable, breathable, and the drop seat zipper works great!

I purchased this one piece wonder for my husband so that he can more comfortably enjoy our winter activities. And post exercise, it makes a very comfortable lounge before bed ensemble. It is his Superman outfit, sans cape.

Mostly plan on using it when I ski but anticipate using it anytime I need an extra layer of warmth. Really comfortable and love the design.

I have Union suits from a couple different companies. This one stands out as warm and best bathroom experience! Love it